where\(\gamma ^a\)  are the Dirac matrices, \(e_a^{\mu }\) 
is the inverse of the tetrad \(e_{\mu }^a\) ,
\(\Gamma _{\mu }=\frac{1}{8}[\gamma ^a,\gamma ^b]e_a^{\nu }e_{b\nu ;\mu }\) 
are the spin connection coefficients. The metric of the
Schwarzschild black hole can be written as [1]}, [2]}
\(ds^2=&-&(\frac{r-2M}{r-2D})dt^2+(\frac{r-2M}{r-2D})^{-1}dr^2\nonumber \\ &+& r(r-2D)(d\theta ^2+\sin ^2\theta d\phi ^2),\) 
